The study's ultimate design is to chronicle the natural history of HPV in adolescents and young women in a prospective cohort which was established in 1990. The study funded in 2005 was designed to examine the innate and adaptive mucosal immune responses to HPV in the context of HPV acquisition, clearance, and persistence. Over the last 18 years, we have recruited over 1400 women into the cohort, which in total reflect over 20,000 visits and a repository with well over 100,000 stored samples. In the last 4 years have 27 publications with 7 manuscripts submitted over the last 4 months. We now have the opportunity in the next few years to continue monitoring this inimitable cohort as well as begin to mine the valuable repository. We have collected and continue to collect a rich repository of blood, saliva, cervical cells and mucous, vulvar and anal samples. One of our goals over the new few years is to establish more elaborate repository databases. The logging and monitoring of 100,000 samples with continued repository is an immense challenge. One of our aims is to continue studying the mucosal immune response in more depth. We believe this will be critical in discovering novel therapeutic approaches to HPV induced disease since HPV is largely a localized infection. We plan to continue our investigations into innate responses including Toll-like receptors, with a focus on defining the downstream expression of regulatory cytokines. This will include the development of assays to include the important IFN-alpha family thought to be an important cytokine expressed after TLR activation. We also plan to investigator the role of TLRs and regulatory T cells in more depth with studies using flow cytometry. In studying the immune response, we have also focused on the development of the cervix in young women. We continue to examine the role of epithelial topography in women's vulnerabilities to HPV and cancer. We plan to work with bioengineers in development of more sophisticated techniques to measure the process of squamous metaplasia, the cells thought vulnerable to cancer change. Another goal is to capture mucosal immune response in adolescents vaccinated with the HPV vaccine. We plan to recruit an additional 100 sexually active adolescents recently vaccinated with the HPV vaccine to our study of mucosal immune responses. This will allow us to examine mechanisms of protection associated with the prophylactic vaccine. This grant will allow the valuable work of our staff to continue the retention of the cohort as well recruitment of the vaccinated adolescents and to collect the valuable samples. Expansion of immune studies, data analysis and data management will remain centerpieces over the coming years.